Can anyone offer any advice or help on this matter? I have an Imac 17" Intel Core 2 Duo (5,1) 2ghz late 2006 model. Just recently the superdrive has perished for what ever reason & I have read that some times if you reinstall the original operating discs that came with the computer, the superdrive may or may not come back to life. Leopard 10.5.8 with all the updates is the current set up on the imac & I want to put Tiger 10.4.7 back on it. So I'm connecting the Imac to my Mac pro 15.4" (late 2007 model - 2.2ghz 4gb ram intel core 2 duo) via firewire & use the Imac as a target disk. I put the install disc into my mac pro with the imac connected, power down - reboot holding 'C' to boot up the Tiger install disc. The apple logo & spinning wheel appear, but then the screen darkens & a 'You must turn off your computer or hold the power switch for a few seconds appears' Now I've tried resetting the PRAM,NVRAM & SMC also decreasing the amount of RAM there is in the laptop. But the error is always the same?? However if I put leopard 10.5.6 disc in that starts ok, snow leopard 10.6 that starts ok too. But tiger 10.4.7 & leopard 10.5.1 won't start at all?? How can I get Tiger 10.4.7 back onto the imac using my mac pro? Yes the only other way is to replace the superdrive, but I'm not in a position to get it replaced at the minute & if reinstalling the original operating discs rejuvenates the old superdrive, then there's no point. Thanks for reading & taking the time to offer any help.